The present invention relates to a 1.5 stage symbiotic hybrid vehicle architecture and integral propulsion system for a reusable space access launch vehicle.
In order to continue, expand and maximize the utilization of space for orbital or interplanetary operations, it is necessary to develop a cost effective means to access space on a regular basis. Various launch vehicle architectures have been evaluated to derive the best approach to accomplish cost-effective space access.
The generally accepted premise for cost effective access to space is to use a fully reusable launch vehicle because the cost of hardware can be amortized over many flights, as opposed to expendable launch vehicles that must be fabricated, paid for, and expended for each individual space mission. Another launch vehicle element that has a significant impact on cost of space access is the number of stages configured into the launch vehicle. The cost of vehicle development and operations is proportional to the number of stages configured into the vehicle. Consequently, an optimal approach to space access would consist of a single stage to orbit reusable launch vehicle because it is fully reusable and has only a single stage.
Increasing the number of stages in a launch vehicle, however, has the benefit of reduced overall vehicle size, along with a required level of propulsion technology that is inversely proportional to the number of stages. A launch vehicle with multiple stages does not generally demand a high level of propulsion technology; conversely, reducing the number of propulsion stages requires a larger vehicle size and more demanding propulsion technology level. The most recent NASA experience with development of single stage to orbit reusable launch vehicles has demonstrated that the technology required to support and make this approach feasible is not yet available.
Therefore, in order to achieve reusable launch vehicle technical feasibility, people have focused on a two stage to orbit reusable launch vehicle approach to achieve cost-effective space access. The two stage to orbit approach offers full vehicle reusability, but it is estimated that it will require: (1) relatively high non-recurring development costs; and relatively complex vehicle architecture. The development of two reusable stages results in high non-recurring costs because it requires development programs for a fully reusable flyback booster and a reusable orbiter. Moreover, the relative complexity inherent in the two stage to orbit reusable launch vehicle approach can, to an extent, offset the cost benefits of reusability and result in increased recurring costs as well.
Accordingly, it is an object of the present invention to provide a reusable launch vehicle system which provides cost effective space access
It is a further object of the present invention to provide a reusable launch vehicle system which has a 1.5 stage symbiotic hybrid vehicle architecture and an integrated propulsion system.
The foregoing objects are attained by the reusable launch vehicle system of the present invention.
In accordance with the present invention, a reusable launch vehicle system broadly comprises a reusable vehicle, at least one expendable boost propulsion device attached to the reusable vehicle, and an oxidizer system onboard the vehicle. The oxidizer system supplies oxidizer, preferably in a gaseous state, to the at least one expendable boost propulsion device. In a preferred embodiment of the present invention, the at least one expendable boost propulsion device comprises a hybrid rocket combustor.